The actual MK14 board is under all the wiring of an additional board I added later

I have been interested in electronics since I was 10 years old. My father was a tinkerer and we always had hand build radios and stuff around the house since I remembered. When I was in boarding school, yes, like Hogwarts but without too much magic, I started reading about digital circuits. Then this microprocessor kit came on the market, the MK14. Here are the specs:

The MK-14 was a training board sold in kit form
Cost £39.95
CPU: National Semiconductor SC/MP 8-bit processor
256 bytes of RAM
512 bytes of ROM with the basic drivers
9 7-segment red LED display
membrane keypad
some additional I/O ports

I bought this kit with money I saved and built in bit by bit during boarding school study hall time hiding in the common bathroom because it has a large window for the soldering smoke to air out. I vividly remember the head master caught me, asked me what it was, and said something like “interesting” and left. I took that as a official permission to keep skipping study hall for the next few days to finish the soldering.

Creativity and Logic

Learning microprocessor architecture, how to program in assembly language, and then do the assembly by hand really set my study and career choice. I ended up at Imperial College studying Computing Science. The MK14 experience was a combination of absolute logical thinking, and creativity. Programming a tiny computer is creative? Thinking up something fun to program, make that works with a keypad and a 7-segment LED display, then fit it into 256 bytes of RAM. That requires creativity.

MK14 History

Reading the history of the MK14, perhaps Sir Clive Sinclair was not too enthusiastic about it at the beginning. His partner Chris Curry was more involved. But Sinclair later come out with the ZX80, ZX81 and the Spectrum, which have started may other computing careers around the world. Most people will think of the ZX80 and Clive Sinclair and the start of the affordable hobby computer revolution. Some of us will go a bit further back in history with the MK14.

Photos

All the photos above are taken many years after I have added other circuitry to the MK14. The large capacity and transformer on the left is a power supply. The PCB with all the hand wiring contains some additional IO chip and a music / sound generator. The keypad is hand built, and the LED display I remember is the original display, desoldered from the main board.

Here is a photo of an actual MK14. Credit to Andrew Steers.